I have a Giant Rapid (2010 model 1) and really enjoy it. I tried Specialized and Trek as well but thought the Giant was the best of the three for equipment, fit, and ride. Also, it was sold by the best LBS in the area, which was a factor.

That said, I occasionally have heel strike and note that the Specialized frame would have avoided that. Check you heel when you pedal and look at the clearance when it crosses the chain stays. Make sure it's plenty while wearing your bicycle shoe.